1. Field of the Invention
The present invention relates generally to security systems for aiding authorities in the apprehension of bank robbers and the recovery of stolen monies, and more particularly, to security systems employing currency packs disguised as bundles of currency bills for discharging tear gas, dye, smoke and/or other chemicals in the event of a robbery.
2. Description of the Relevant Art
Among the devices which have been used by banks and other financial institutions to deter bank robberies, and to aid in the apprehension of a thief and the recovery of stolen monies, are security dye packs disguised as a strapped bundle of currency bills. Such security dye packs are normally kept in a teller drawer along with actual currency bills and are handed to a robber by the teller during a bank robbery. The top and bottom faces of the security dye pack are concealed by actual currency bills to simulate actual bundles of currency bills. The disguised security dye packs actually conceal metal canisters containing tear gas, visible dye, tracer dye (rare earth oxide), smoke and/or other active chemicals which can be discharged from the security dye pack to assist in the recovery of stolen monies; and to assist in the apprehension of an assailant.
Tear gas helps to hinder the robber, making it more difficult for the robber to escape from the scene of the crime. Dye serves to stain any bills in the vicinity of the security dye pack, making such bills unspendable and easier to trace; the dye also may stain the skin and clothing of the robber, making it easier for authorities to identify the robber. Smoke provides a visible signal for authorities to follow to help locate the robber and the stolen funds. In addition, such security dye packs often emit a loud bang upon being expended, tending to confuse the robber and aiding authorities in apprehending the robber.
Metal canisters are commonly used to contain the active chemicals that are emitted by the security dye pack after being ignited. The chemical mixture contained in such security dye packs typically includes combustion chemicals similar to those used in a flare; once ignited, these chemicals burn for approximately one minute. High temperatures are created when the active chemicals are ignited by a heat-generating electrically-actuated squib. The walls of the metal canister help to contain heat that might otherwise cause the security pack to catch fire and become engulfed in flames. Clearly, the danger of fire within banks and other financial institutions is a risk that must be minimized. However, the metal canisters are also relatively thick and rigid.
Several methods have been used to actuate such security dye packs upon unauthorized removal from a protected premises. For example, some security dye packs are normally kept in the teller drawer on a magnetic keeper plate. A magnetic reed switch within the security dye pack disables the unit from detonating so long as the reed switch is within the influence of the magnetic field of the keeper plate. Once removed from the keeper plate, a timer is activated, and when the timer has reached a predetermined count, the canisters are activated to deploy the active chemical agents. Another variety of such security dye packs includes a plug anchored by a pull wire to the teller drawer; removal of the security dye pack from the teller drawer causes the plug to be removed from the unit, thereby arming the device. Such security dye packs are generally described, for example, within U.S. Pat. No. 3,303,592 issued to Harner; and within U.S. Pat. No. 3,424,122 issued to De Angelis.
More sophisticated security dye packs contain miniature radio receivers which are tuned to receive a localized radio signal broadcasted by an antenna in the vicinity of the entry doors to the bank. The transmitted signal is limited to the vicinity of the doors and does not normally extend to the teller area. If a security dye pack is handed to a robber and is thereafter brought into the field of the broadcasted radio signal, the transmitted signal is detected by the radio receiver to arm the security dye pack. The security dye pack may then immediately be detonated, or a time delay circuit can hold off detonation of the chemical canisters for a predetermined amount of time to permit the robber to first exit the premises. Modern security dye packs often include a hold-off circuit preventing the security dye pack from being detonated until the robber has left the field of the transmitted signal. In addition, modern security systems often employ digital coding techniques to minimize the likelihood of inadvertent detonation due to stray radio signals generated by other electronic equipment within the banking environment. Examples of such radio-activated security dye packs are those generally described within U.S. Pat. No. 3,564,525, issued to Robeson, et al., and reissued as Reissue U.S. Pat. No. Re. 27,618; U.S. Pat. No. 3,781,860 issued to Freyling, Jr.; U.S. Pat. No. 3,828,341 issued to Carter, Jr., et al.; U.S. Pat. No. 4,511,888 issued to Bernhardt: U.S. Pat. No. 4,559,529 issued to Bernhardt; and U.S. Pat. No. 4,604,607 issued to Sanderford, Jr., et al.
Unfortunately, as the technology of such security dye packs advances, so does the knowledge and experience of assailants. For example, older security dye packs had relatively rigid edges that could not be fanned to see the edges of individual bills. Accordingly, robbers could easily detect a security dye pack by fanning the edges of each currency bundle. Modern security systems use actual currency bills loosely sewn together for allowing the edges to be fanned by a robber without alerting the robber to the true nature of the security dye pack.
Moreover, the metal canisters containing the active chemicals and related electronic components and circuit board within such security systems are usually relatively rigid. The security dye pack would therefore have a hard, rather than soft, feel when handled. In the past, such security dye packs would make a distinctive sound when the security dye pack is rapped upon a teller counter. Experienced bank robbers have been known to rap currency bundles upon the teller counter before leaving the bank to detect the true identity of a security dye pack, and to leave the security dye pack within the bank before making their escape. This problem has largely been dealt with in the past by placing thin foam cushions above and below the rigid components within the security dye pack to cushion such rigid components when the unit is rapped on a hard surface.
Another method which has been used by knowledgeable robbers to quickly determine whether a bundle of currency is genuine is to bend the bundle of bills. An actual bundle of currency bills is flexible enough to be bent along the central portion thereof toward a U-shaped configuration. On the other hand, due to the rigid metal canisters and circuit boards hidden inside most security dye packs, such units can not easily be bent about their centers. Knowledgeable robbers have been known to test currency bundles handed to them by a teller/cashier by bending such bundles to quickly detect any bogus bundles.
ICI Aerospace Division of ICI Americas Inc., based in Valley Forge, Pa., has introduced a security dye pack under the registered trademark "SecurityPac", available as Part No. PN 50000443, also known as the "FlexPac", wherein a single, relatively large, rigid metal chemical canister is positioned within the central portion of the security dye pack. Rigid circuit boards are positioned upon opposing sides of the chemical canister and are connected to each other by a flexible mylar interconnect strap having electrical conductors embedded therein. A first bendable joint is formed between the canister and the first rigid circuit board on a first side of the canister. A second bendable joint is formed between the canister and the second rigid circuit board on the opposing second side of the canister. In this manner, the resulting security dye pack can be bent into a generally S-shaped structure. This commercial product appears to correspond with the device described in issued U.S. Pat. No. 5,059,949 issued to Caparoni et al. and assigned to ICI Americas Inc. The aforementioned "FlexPac" security dye pack is generally more flexible than past security dye packs; however, such "FlexPac" security dye packs are unable to be bent upon their centers since the rigid chemical canister is positioned squarely in the middle of the unit.
Accordingly, it is an object of the present invention to provide a security dye pack disguised as a bundle of currency bills for assisting in the apprehension of a robber, and in the recovery of stolen monies from a protected premises, wherein such security dye pack eliminates the need for rigid metal chemical canisters, and thereby allows the security dye pack to have a softer feel.
It is a further object of the present invention to provide such a security dye pack which is largely flexible along a significant portion of its length to facilitate bending of the unit.
A still further object of the present invention is to provide such a security dye pack which more closely resembles the feel of an actual bundled stack of bills to help avoid detection by knowledgeable thieves.
Yet another object of the present invention is to provide such a security dye pack which does not present a significant risk of fire when the security dye pack is ignited.
These and other objects of the present invention will become more apparent to those skilled in the art as the description thereof proceeds.